Batch and Continuous Methods for Evaluating the Physical and Thermal Properties of Films

Thin films and membranes are used in a number of commercial applications, including energy products (e.g. photovoltaics, batteries, and fuel cells) and separation processes (e.g. pervaporation, reverse osmosis, dialysis, etc.). According to the 2016 BCC report titled “Global Markets, Technologies and Materials for Thin and Ultrathin Films”, the market for thin films is expected to rise from the 2015 global demand of US $9.8 billion at an annual rate of 3%. In order to meet this demand, thin film manufacturing processes need to be effective at large-scale and must consistently meet quality standards to ensure high-quality and high-performance.

To enable high-throughput manufacturing while still maintaining high-quality thin films, quality control measures that limit internal or surface defects are essential. Quality of film is dependent on both the interrelated physical properties (e.g. density, porosity, heat capacity, etc.) and the quality of materials used in construction. While there have been in-line methods developed to detect, identify, and quantify issues with quality, many of these methods remain unreliable, difficult to employ, and costly. Therefore, there is a need for fast, reliable, non-destructive, and cost-effective, in-line evaluation of thin films and membranes.

Description

Scientists at NREL and ORNL have developed a method of continuous monitoring of films, membranes, or electrodes produced in large-scale manufacturing lines. These methods involve transferring heat to a film, measuring its thermal response, and correlating the response to a physical property or characteristic of the film. Monitoring films, membranes, and electrodes through these cost-effective thermal methods or systems is highly efficient, easy to implement, and allows for the detection of small changes in porosity, or other properties of the film.